Effect of chemical and bio-fertilizers on the life table attributes of Eisenia fetida

Earthworms are important soil invertebrates and play an important role in improving soil quality. Indiscrete use of chemical fertilizers poses a threat to soil quality. Alteration in the soil chemistry is known to negatively impact the macrofauna of soil, especially, epigeic earthworms. The study aimed to understand the effect of chemical and biological fertilizers on the life table attributes of earthworm, Eisenia fetida. Laboratory adapted E. fetida were reared on artificial soil supplemented with chemical fertilizers, Urea and DAP, and biofertilizers, vermicompost and Rutoz®.It was observed that the presence of urea in soil proved to be detrimental to the biomass accumulation, life span, as well as reproductive potential of the earthworms. Application of urea to the soil harbouring earthworms reduced the weight of individual earthworms from 286±14.24 mg in the control group to 242±12.047 mg as soon as 15 days of the application, while the DAP diminished the earthworm weight to 272±13.54 mg. The effect was more pronounced on the total biomass of the culture owing to the high toxicity of urea. The total mass diminished to one-third,i.e., 1.02±0.05 g on Day 60 as compared to the corresponding control (3.46±0.172 g). The urea and DAP treatment decreased the percent survival of the earthworms by 70% and 40%, respectively.On the other hand, the bio-fertilizers had a positive effect on the earthworms and the biology is comparable to that of the control group. To the best of our knowledge, this is the first attempt to understand the effect of chemical fertilizers on the survival and reproductive fitness of the worms.

The Potential of Local Earthworms in Vermicomposting Goat Manure (GM) and Spent Coconut Flakes (SCF)

Vermicomposting is a process that involves biological, chemical and physical transformations of solid organic materials such as agricultural residues of plant and animal through the use of microorganisms and earthworms. There are three main classes of earthworms, and only those from one class are usually used for vermicomposting. However, mostly foreign earthworms are used in the setup. Foreign earthworms are more expensive and harder to obtain than local earthworms. This makes the local farmers reluctant to try since they are expensive. The difference in vermicompost using two species of epigeic earthworms, a local earthworm and a foreign earthworm (Eisenia fetida), and normal compost without any earthworms was measured in this study. Both species of earthworms were placed in identical vermibeds consisting of partially composted goat manure and partially composted spent coconut flakes (SCF) with the ratio of 5:1 respectively in terms of weight. The vermibed moisture content was maintained at 60 – 70% throughout the whole process. The end products showed a difference from one another. The E. fetida showed a better result compared to the local earthworms in terms of the nutrient content presence and the adaptability of the earthworms during the whole process. However, the end product from the local earthworms was still better compared to the normal compost without any earthworms.

Kitchen waste management by vermicomposting using locally available epigeic earthworm species

A large quantity of kitchen waste is generated in India which is either burnt, left in open or landfilled posing a serious problem of its safe disposal. To mitigate this problem all the kitchen waste can be converted into highly valuable nutrient rich vermicompost using the locally available epigeic earthworms. The biodegradable kitchen waste like vegetables, fruits, food waste etc can be cultured with earthworms to form the vermicompost by using vermitechnology. Since these vermicomposts are rich in nutrients which can replace the chemical fertilizers. In the present study the vermicomposting of kitchen waste has been attempted using locally available epigeic earthworm species of Jammu namely Amynthus diffringens, Metaphire houlleti and Octolasion tyrtaeum. The physico-chemical analysis of generated vermicomposts was carried out and compared with each other and with that of original soil sample that has been added in vermibeds prior to earthworm inoculation and addition of kitchen waste. The average values of macronutrients in the vermicompost produced by O. tyrtaeum were observed to be the highest among all types of vermicomposts i.e. Organic Carbon (OC)- 11.66 ± 0.34% , Nitrogen (N)- 1.17 ± 0.20%, Phosphorus (P)- 2.97 ± 0.32%, Potassium (K)- 1.18 ± 0.15%, Calcium (Ca)- 0.26 ± 0.04%, Magnesium (Mg)- 0.17 ± 0.04%.